Ultrasound-guided placement of an anchor wire or injection of methylene blue to aid in the intraoperative localization and excision of peripheral lymph nodes in dogs and cats

OBJECTIVE To evaluate ultrasound-guided placement of an anchor wire (AW) or injection of methylene blue (MB) to aid in the intraoperative localization of peripheral lymph nodes in dogs and cats. ANIMALS 125 dogs and 10 cats with a total of 171 lymphadenectomies. PROCEDURES Medical records of dogs and cats that underwent peripheral lymphadenectomies with or without (N) the AW or MB localization technique were reviewed. Data retrieved included clinical, surgical, and histologic findings. The proportions of successful lymphadenectomies, lymph node characteristics, and complications among the 3 groups were analyzed. RESULTS 143 (84%) lymph nodes were successfully excised. Lymphadenectomy success was significantly affected by the localization technique, with 94% for group AW, 87% for group MB, and 72% for group N. Lymph node size was smaller in groups AW and MB, compared with group N. Duration of lymphadenectomy was shorter in group AW, compared with groups MB and N, and in group MB, compared with group N. Intra- (7%) and postoperative (10%) complications and final diagnosis did not significantly differ among groups. CONCLUSIONS AND CLINICAL RELEVANCE Both lymph node localization techniques were highly successful and reduced surgery time, compared with unassisted lymphadenectomy. Specifically, these techniques were effective for localization of normal-sized and nonpalpable lymph nodes and were efficient and practical options for peripheral lymphadenectomies, particularly for those that were small or nonpalpable.

Intraoperative localization and preservation of reading in ventral occipitotemporal cortex

Resective surgery in language-dominant ventral occipitotemporal cortex (vOTC) carries the risk of causing impairment to reading. As it is not on the lateral surface, it is not easily accessible for intraoperative mapping and extensive stimulation mapping can be time consuming. Here we assess the feasibility of using task-based electrocorticography (ECoG) recordings intraoperatively to help guide stimulation mapping of reading in vOTC. In 11 patients undergoing extraoperative, intracranial seizure mapping we recorded induced broadband gamma activation (70 - 150 Hz) during a visual category localizer. Word-responsive cortex localized in this manner showed a high sensitivity (72%) to stimulation-induced reading deficits, and the confluence of ECoG and stimulation positive sites appears to demarcate the visual word form area. In two additional patients, with pathologies necessitating resections in language-dominant vOTC, task-based functional mapping was performed intraoperatively using subdural ECoG, alongside direct cortical stimulation. Cortical areas critical for reading were mapped and successfully preserved, while enabling pathological tissue to be completely removed. Data collection is possible in <3 minutes and initial intraoperative data analysis takes <3 minutes, allowing for rapid assessment of broad areas of cortex. Eloquent cortex in ventral visual cortex can be rapidly mapped intraoperatively using ECoG. This method acts to guide high-probability targets for stimulation, with limited patient participation, and can be used to avoid iatrogenic dyslexia following surgery.

Pre- and intraoperative thoracic spine localization techniques: a systematic review

OBJECTIVE In the era of modern medicine with an armamentarium full of state-of-the art technologies at our disposal, the incidence of wrong-level spinal surgery remains problematic. In particular, the thoracic spine presents a challenge for accurate localization due partly to body habitus, anatomical variations, and radiographic artifact from the ribs and scapula. The present review aims to assess and describe thoracic spine localization techniques. METHODS The authors performed a literature search using the PubMed database from 1990 to 2020, compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of 27 articles were included in this qualitative review. RESULTS A number of pre- and intraoperative strategies have been devised and employed to facilitate correct-level localization. Some of the more well-described approaches include fiducial metallic markers (screw or gold), metallic coils, polymethylmethacrylate, methylene blue, marking wire, use of intraoperative neuronavigation, intraoperative localization techniques (including using a needle, temperature probe, fluoroscopy, MRI, and ultrasonography), and skin marking. CONCLUSIONS While a number of techniques exist to accurately localize lesions in the thoracic spine, each has its advantages and disadvantages. Ultimately, the localization technique deployed by the spine surgeon will be patient-specific but often based on surgeon preference.

Intraoperative Ultrasound in Colorectal Surgery

Intraoperative ultrasound (IOUS) in colorectal surgery can be used both in benign and in malignant lesions. In benign cases, such as Crohn’s disease and diverticulitis, it can orient toward the extension of the surgical intervention. In malignant cases, such as colorectal cancer with liver metastases, IOUS/CE-IOUS (contrast-enhanced) improved the intraoperative management of liver metastases by dictating the resection margins in relation to the tumor extension. The IOUS method allows for exact tumor location, intestinal wall visualization, and malignant tumor penetration. The IOUS revealed the tumor and its margin in rectal lesions, making the sphincter-sparing operation easier to perform. In patients with small polyps and early colon and rectum cancers, IOUS works well as a one-of-a-kind intraoperative localization technique. In comparison with IOUS, CE-IOUS offered better detection and resection guidance. Intraoperative ultrasound enables surgeons to easily localize small, non-palpable lesions of the large bowel. Furthermore, it can determine even the aggressive potential of these lesions with high precision.

Flexible ureteroscope with ultrasound guidance for treatment of parapelvic renal cysts: A complementary approach to locate the cystic wall

Background The main treatment of parapelvic cysts is flexible ureteroscope currently. Considering the intraoperative localization of the cyst may fail with flexible ureteroscope, we tend to use an innovative method by ultrasound-guided for easily locating cystic wall during flexible ureteroscopic surgery Methods We retrospectively reviewed 17 consecutive cases of parapelvic renal cysts treated by ultrasound-guided flexible ureteroscope between March 2017 and May 2020. The differences of simple flexible ureteroscopic technique and ultrasound-guided flexible ureteroscopic technique were compared. The surgical procedures, postoperative complications, results and patients’ follow-ups were evaluated. Results The cysts wall were seen clearly in 10 patients with ureteroscopic vision. Another 7 patients changed to ultrasound-guided flexible ureteroscopic surgery since it was difficult to identify the cyst wall. Mean operative time were 25.9 ± 8.7 minutes and 37.1 ± 10.1 minutes for conventional and modified technique respectively (P =0.004), of which 17.6 ± 5.8 minutes and 26.5 ± 8.4 minutes to search the cysts, respectively (P = 0.002), and the mean time of the incising were 7.1 ± 4.9 minutes and 12.1 ± 5.6 minutes, respectively (P = 0.000). All of the patients were followed-up 12 months, there were no serious complications and recurrence observed. Conclusions We demonstrated that it is feasible and safe to treat parapelvic renal cyst by ultrasound-guided flexible ureteroscopic incision and drainage. The less sample size and further studies were the limitations of our study.

Preoperative Localization in Colonic Surgery (PLoCoS Study): a multicentric experience on behalf of the Italian Society of Colorectal Surgery (SICCR)

The aim of this prospective multicentric study was to compare the accurate colonic lesion localization ratio between CT and colonoscopy in comparison with surgery. All consecutive patients from 1st January to 31st December 2019 with a histologically confirmed diagnosis of dysplastic adenoma or adenocarcinoma with planned elective, curative colonic resection who underwent both colonoscopy and CT scans were included. Each patient underwent conventional colonoscopy and CT to stage the tumour, and the localization results of each procedure were registered. CT and colonoscopic localization were compared with surgical localization, adopted as the reference. Our analysis included 745 patients from 23 centres. After comparing the accuracy of colonoscopy and CT (for visible lesions) in localizing colonic lesions, no significant differences were found between the two preoperative tools (510/661 vs 499/661 correctly localized lesions, p = 0.518). Furthermore, after analysing only the patients who underwent complete colonoscopy and had a visible lesion on CT, no significant difference was observed between conventional colonoscopy and CT (331/427 vs 340/427, p = 0.505). Considering the intraoperative localization results as a reference, a comparison between colonoscopy and CT showed that colonoscopy significantly failed to correctly locate the lesions localized in the descending colon (17/32 vs 26/32, p = 0.031). We did not identify an advantage in using CT to localize colonic tumours. In this setting, colonoscopy should be considered the reference to properly localize lesions; however, to better identify lesions in the descending colon, CT could be considered a valuable tool to improve the accuracy of lesion localization.

Design of ultra-wideband antenna for the localization of pulmonary lesions during thoracoscopic surgery

Biopsies or surgical excisions for diagnosis should be taken for pulmonary lesions which show evidence of growth or are larger than 8 mm. This is usually performed by video-assisted thoracoscopic surgery. To improve the intraoperative localization of these lesions, we propose to add an ultra-wideband antenna directly on a thoracoscopic tool and locate the lesion through microwave imaging. Here the design of an antenna for such a goal is undertaken. Numerical simulations are used to quantify the influence of a fictional lung lesion on the signal recorded by a bowtie antenna of different lengths (2 to 6 cm) and widths (0.5 to 1.5 cm). It is found that the most important design parameter is the total length of the antenna. The width of the antenna, instead, affects only marginally the signals, but it has a limited effect for deeper lesions

Neuronavigation system in neurosurgery: Technical details and our early clinical experiences

Introduction: Image-guided surgery is the need of time in neurosurgery. The use of neuronavigation has a significant impact on various neurosurgical procedures. We report our clinical experience and surgical techniques of neuronavigation assisted intracranial and spinal surgeries. Materials and Method: This is observational longitudinal study of 65patients who underwent surgeries using navigation system in the department of neurosurgery, National Neurosurgical Referral Center, National Academy of Medical Sciences (NAMS) Bir hospital and National Trauma Center, over the period of one and a half year. Description of Navigation techniques, its applications and surgical outcome were studied. Medtronic Stealth station 7 and Brain Lab Curve Neuronavigation system, which can be used as both frame based and frameless image guided system were employed in this study. Results: We used Neuronavigation system in 60 cases of cranial procedures and 5 cases of spinal stabilizing procedures. Among intracranial surgeries we utilized this system to effectively make bone flaps and burr holes, to detect critically located deep-seated, subcortical and skull base tumors and to operate on intra parenchymal lesions with grossly unclear margins. Neuronavigation system was used in 5 cases of spinal procedures for pedicle screw placement. Conclusion: Neuronavigation is a tool that provides numerous advantages to the neurosurgeon like more accurate planning approach, ability to use smaller approaches, higher precision for intraoperative localization of different anatomical structures and offering greater surgical safety. This technique, although apparently very complex in the beginning, becomes very user-friendly gradually and positively appreciated by everyone who uses it, after going through a relatively short learning curve.